To check this you should use Query Inspector. Query Inspector shows query requests and responses.

A guide on how to use it you can find [here](https://community.grafana.com/t/using-grafanas-query-inspector-to-troubleshoot-issues/2630).
<!---So make sure to check the query sent and the raw response, learn how in this guide: [How to troubleshoot metric query issues](https://community.grafana.com/t/how-to-troubleshoot-metric-query-issues/50)--->